Semiconductor chips are electronic components that exploit the electronic properties of semiconductor materials, principally silicon, germanium and gallium arsenide. Semiconductor chips are manufactured both as single discrete devices and as integrated circuits (ICs), which consist of a number of devices manufactured and interconnected on a single semiconductor substrate.
Semiconductor chips, for example, the processor chips to be used in mobile handsets may have a boot read-only memory (ROM) with boot code integrated into their silicon so such a chip could perform quite sophisticated boot sequence on its own and load boot programs from various sources like NAND flash, SD or MMC card and so on. Also a boot ROM is often able to load boot loader or diagnostic program via serial interfaces like UART, SPI, USB and so on.
Semiconductor chips may be equipped with a one-time programmable (OTP) memory. The OTP memory is a field-programmable logic array (FPLA) that it may not be updated and reused after its initial programming. In other words, the OTP memory may be programmed once and may not be subsequently reprogrammed. The data stored in the OTP memory may be used for various customer specific applications such as, for example, enabling configuring chip usage features, authenticating any secondary boot images (for example, NOR, NAND, USB, UART flashes), authenticating any other codes running on the chip, etc.
Semiconductor chips may have one or more of the plurality of debug interfaces. Debug interfaces provide access capabilities used by test and/or debug tools for testing and/or debugging semiconductor chips or devices. Examples of debug interfaces may include JTAG access ports, trace auxiliary ports, snoop interfaces, etc.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.